Formal Lossen Rearrangement/Alkenylation or Annulation Cascade of Heterole Carboxamides with Alkynes Catalyzed by CpRh III Complexes with Pendant Amides
| Autor: | Ken Tanaka, Takayuki Yamada, Yu Shibata |
|---|---|
| Rok vydání: | 2019 |
| Předmět: |
chemistry.chemical_classification
Annulation 010405 organic chemistry Aryl Organic Chemistry Alkyne General Chemistry 010402 general chemistry 01 natural sciences Medicinal chemistry Catalysis Reductive elimination 0104 chemical sciences chemistry.chemical_compound Cyclopentadienyl complex chemistry Lossen rearrangement Amide Moiety |
| Zdroj: | Chemistry – A European Journal. 25:16022-16031 |
| ISSN: | 1521-3765 0947-6539 |
| DOI: | 10.1002/chem.201904156 |
| Popis: | It has been established that a cyclopentadienyl (Cp) RhIII complex with two aryl groups and a pendant amide moiety catalyzes the formal Lossen rearrangement/alkenylation cascade of N-pivaloyl heterole carboxamides with internal alkynes, leading to alkenylheteroles. Interestingly, the use of sterically demanding internal alkynes afforded not the alkenylation but the [3+2] annulation products ([5,5]-fused heteroles). In these reactions, the pendant amide moiety of the CpRhIII complex may accelerate the formal Lossen rearrangement. The use of five-membered heteroles may deter reductive elimination to form strained [5,5]-fused heteroles; instead, protonation proceeds to give the alkenylation products. Bulky alkyne substituents accelerate the reductive elimination to allow the formation of the [5,5]-fused heteroles. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
| Nepřihlášeným uživatelům se plný text nezobrazuje | K zobrazení výsledku je třeba se přihlásit. |